The present invention relates to a rear vehicle-body structure of a vehicle, and in particular, relates to the rear vehicle-body structure of the vehicle which is provided with rear side frames.
A structure of a vehicle, such as an automotive vehicle, in which a crash can is interposed between a rear bumper reinforcement extending in a vehicle width direction and a rear side frame extending in a vehicle longitudinal direction at a rear portion of a vehicle body so that when an impact load is applied from behind the vehicle body in a rear face collision (rear collision), the crash can is crushed in a folded manner so as to absorb impact energy, is known.
Further, a structure which improves the impact-energy absorption performance in the vehicle rear collision by using the rear side frame is known. Japanese Patent Laid-Open publication No. 2011-056997, for example, discloses a structure in which a linear-shaped recess portion is formed at a ridge line of a metal-made hollow pole-shaped member which is applicable to the rear side frame such that an angle which the line-shaped recess portion forms with a direction of the ridge line is within a range of 20-70 degrees, thereby improving the impact-energy absorption performance by generating bellows-shaped buckling when the impact load is applied in an axial direction of the pole-shaped member.
In recent years, it is required for the vehicle, such as the automotive vehicle, to further improve the impact-energy absorption performance in the vehicle rear collision to improve the safety of passengers in a cabin, specifically to further increase the amount of impact-energy absorption when the impact load is applied from behind the vehicle body in the vehicle rear collision.